Which of the following are CLIA ’88 requirements for the use…

Which of the following are CLIA ’88 requirements for the use of quality-control materials? 1. At least two control samples of different concentrations must be tested every 24 hours. 2. At least one blood-gas control sample must be tested every 8 hours. 3. Both high and low blood-gas control materials must be tested every 24 hours. 4. At least one calibrator or control must be tested each time a patient sample is tested.